Permanent magnet assembly



y 1953 N. s. MORETON 2,645,745

PERMANENT MAGNET ASSEMBLY Filed April 17, 1952 3 SheetsSheet l Witnesses INVENTOR.

Q e I W Neal Morel'orl,

W Hm His H'orney.

July 14, 1953 N. s. MORETON PERMANENT MAGNET ASSEMBLY 5 sheat s-Sheet 2 Filed April 17, 1952 INVENTOR.

Neal. SI MOreTDn W H His Attorney.

QMWM Max:109 W Witnesses July 14, 1953 N. s. MORETON 2,645,745

PERMANENT MAGNET ASSEMBLY Filed April 17, 1952 3 Sheets-Sheet 3 I V I4 Witnesses INVENTOR.

Neal s. MoreTon, $335 W flaw His Altorney Patented July 14, l953 UNITED STATES PATENT- OFFICE");

PERMANENT MAGNET ASSEMBLY Neal S. Moreton, Staten Island, N. Y. Application April 17, 1952, Serial No. 282,844

2 Claims.

This application is a continuation-in-part of application Serial No. 35,167, filed June 25, 1948, now abandoned.

The high strength permanent magnets of the aluminum nickel cobalt type usually require pole-shoes and some form' of supportingframe which has been difficult to provide due'to the hardness and brittleness of the magnet material. This invention is intended to cast the supporting frame uniting the magnets and associated pole shoes with a non-magnetic material having the properties of setting in place and wetting or bonding to the magnets and pole shoes. This construction is particularly advantageous in magnetic separators for removing tramp iron. Another feature is a magnetic cement which sets up without the porosity accompanying evaporation of solvent, securing the pole shoes to the magnets.

In a preferred form, the binding ingredient for the cast frame and for the cement is a solventless varnish. This varnish or resin is a fluid which sets to the solid state without the evolution of volatile matter, at a rate determined by a catalyst. Further objects and advantages appear in the specification and claims. V

Inthe accompanying drawings, Fig. 1 is a perspective of a pulley type magnetic separator;

Fig. 2 is a perspective of a plate type magnetic separator associated with a conveyor belt; Fig. 3 is a perspective of a chute type magnetic separator; Figs. 4, 5, and 6 are views of permanent magnets forming part of the pulley and plate type magnetic separators; Figs. 7 and 8 are perspectives of a hinged magnetic separator plate using the permanent magnet of Fig. Fig. '9 is a top plan View of a magnetic separator plate using the permanent magnet of Fig. 6; Fig. 10 is a section on line aa of Fig. 9; Fig. 11 is a section on line bb of Fig. 9; Fig. 12 is a top plan view of another magnetic separator plate; Fig. 13 is a section on line 0-0 of Fig. 12; and Fig. 14 is a section on line cld of Fig. 12; Fig. 15 is a top plan view of another magnetic separator plate; Fig. 16 is a section on line g-g of Fig. 15; Fig. 1'7 is a section on line ff of Fig. 15; Fig. 18 an end view of the Fig. 15 plate; Fig. 19 is a side view, partly in section on line h-h of Fig. 20 of a solid hub magnetic separator; Fig. 20 is an end view, partly in section, on line k-7c of Fig. 19;

Figs. 21 and 22 are fragmentary views illustrating the attachment of the pole shoes by a magnetic cement; Fig. 23 is a side view, partly in section, on line m-m of Fig. 24 of a'hollow hub magnetic separator pulley; Fig. 24 is an end view,

partly in section, on line nn of Fig. 23; and Fig. Fig. 25 is a perspective of another magnetic sep a: rator plate.

Referring to the drawing, Fig. 1 shows a typical pulley type magnetic separator having a pulley I over which runs a conveyor belt 8 carrying non-magnetic material 2 such as textile fibers, grain, coal, or liquids from which it. is desired to remove tramp iron or particles of ferrous or magnetic material indicated generally by the reference numeral 3. The pulley containspermanent magnets 4 which cause the magnetic material to be held against the conveyor belt until forcibly removed as the belt runs off the underside vof the pulley. In Fig. 2, the conveyor belt runs over a conventional pulley I, moving-the non-magnetic material under plate type magnet 9 having permanent magnets 5 which attract the magnetic material. In Fig. 3, the non-magnetic material is fed through the chute 23 having a hinged plate It in its bottom wall carrying permanent magnets which pick up the magnetic material. The hinging'of the plate It! permits convenient removal of the adhering magnetic particles when the chute is not in use. Figs. 1, 2,

and. 3 indicate typical magnetic separator installations.

In each of these separators, permanent magnets of high strength material, such as "Alnico are used. In order to obtain the most effective separation, these magnets require soft iron pole shoes to obtainthe proper magnetic flux distriless varnish or resin, a catalyst and a filler such I as talc, glass fiber or other textile fibers orfillers. The purpose of the filler is to increase the strength or other mechanical properties of the compound. One type of solventless varnish or resin employed in this compound, for example, is an unsaturated polyester of the addition polymerization type. Another type of solventless varnish or resin employed in the'compound used in this invention, for example, is a condensation polymerization type having the property of curing to its final state without the evolution-of volatile matter. The unsaturated polyester (addition polymerization type) of solventless-varnish or resin also has the property of setting up from the liquid to the solid or cured state without the evolution of volatile matter. These varnishes produce a dense non-porous structure and also have the property of wetting metal and producing a strong metal to resin bond.

In order to increase the effectiveness of the magnetic pull of the magnets, the pol shoes are preferably attached to the magnets by a cement containing powdered magnet material. Such a cement may contain asolventless varnish, a catalyst, and powdered Alnico. A similar result may be reached by a mixture of powdered metals corresponding to the analysis of Alnico or other suitable permanent magnet material. The solventless varnish ingredient in the cement may be an unsaturated polyester of the addition polymerization type or the condensaion polymerization type which cures without the evolution of volatile matter. Thi cement sets in place and forms a good bond between each pole face of the permanent magnet and its correspondingpole'shoe and in addition to eliminatingthegap between th pole faces of the magnet and their corresponding pole shoes, it'alsoprevents the casting compound of the framestructure, from flowing in 'betweenthe-magnet pole facesand their corresponding pole shoes.

' Thetmagnetic-cement, in eifect, becomes apart ofthepermanent magnet, thereby improving the effectiveness of the magnet assembly even though thezpole surfaces of the magnet are not. carefully ground .to .fit the pole shoes.

Th following isan example of the casting'compound forthe supporting frame:

Parts by Weight Solventless varnish (Unsaturated polyester addition -;polymerization in) 1 ,fllerltiargxhutyl perbenzoate or benzoyl peroxide (Cat- -a 'st Fillei' 6 An alternate example of casting compound:

Partsby weight 'Solvcntless varnish (Condensation polymerization type that cures without evolution of volatile matte 110.0 Benzoyl dimethylamine (Catalyst) F- 11.0 Filler 1.

An example of the magnetic cement employed:

Parts by weight Solventless varnish (Unsaturated polyesteraddition polymerization type) 1.4.80 :Tertiar butyl perbeuzoate orbenzoyl peroxide (Cat- 1 117st 0 'Pow dered Alnico magnet material 80.00

An alternate example of magnetic cement:

Parts by weight Solventless varnish (Condensation polymerization .type.,that cures without evolution of volatile platter) .'1 :Benzoyl dimethylamine (Catalyst) .Rowdered ,Alnico magnet material 8 The powdered A1nico,magnet material in either ofthe two examples of cement given may be-substituted by the following:

OUDOl 'Partshy Weigh iEowdercd aluminum 6.0,8 .Powderedcobalt" 20 .04 Powdered nickel 11.09 .Powdered copper- 3.50 Powdered iron. 40.24

plates, the pole shoes which may be strips of soft iron (steel) II and I8 may be placed in a mold with the outer or working faces down. Magnetic cement may be applied on the upper faces of the strips and the permanent magnets placed on the strips and worked around so as to squeeze any excess magnetic cement from between the magnet and the associated pole shoes. The magnetic cement will usually form a bead IT at the sides of the magnet, as indicated in'Figs. 21 and 22. After themagnets are locatedon-the pole shoes, other components may be added and the casting compound is poured into the mold where it sets up ;insitu when converted to its cured or final state by cold setting or by the application of heat.

In the-structure shown in Figs. '7 and 8 where the .cast material extends beyond the edges of the pole shoes and must have sufficient strength atxits edges to carry the Weight, it may be desirable to lay fibrous reinforcing material into the 'moldatthe points ,ivhere reinforcement is desired. ;In'const1?ucti ons:such as shown in Figs. 17 and 18, the casting compound merely-embeds the central parts ofithepole shoes l8. .With this construction, mgr-eater thickness is necessary at the -:center to provide sufficient mechanical strength.

In ;the pulley typeseparators-shown inFigs. 19-and 20, the pulley-shaft t-SYhasnon-magnetic end flanges-i6 fixed thereto. Between the flanges are fixedspaced-axially extending poleshoes 13 which .-have .curved surfaces corresponding to the-desired outer, surface ofthe pulley. The magnetsskhave curved poles which bridgethe under sides ofthe; pole ,shoes [3. The permanent magnets ,will ordinarily be cemented to the pole shoes before thepoleshoes aremounted on theflanges t6. ,Afteix-assemblm-a sheet is wrapped around the pole shoes 13 to close the spaces between the pole .shoesand casting-compound M poured into thednteriorthrough anopening a: in one of .the flanges 125. After setting, the wrapping sheet is rremoved rand a smooth= pulley surface is obtainedinyvhichthecasting'compound I4 is substantially fiush with, -or-a continuation of the outer working surfaces ofthe'pole shoes [3. In alargerdiameter pulley type separator in: order to :cut 'down .the amount of casting material, and qflanges 20 .mountedon a shaft ,2 I are provided with inwardly extending flanges .25 .which carry a cylinder ..22:-spac,ed slightly inward from the permanent. magnets 4. .In this construction, .theopening a: through which the casting com- .pound is poured into themold cavity islocated inone of.the.end flangeslfl between the cylinder 26-and the outer surface of the .pulley.

.In all .these constructions, the casting compoundfiows aroundthe poles ,of the magnet and the adjacentfaces of the pole shoes and in the spacebetween the spaced poleshoes and provides a smooth surface which is substantially flush with ,the-outer exposed working surfaces of the pole-shoes. .The characteristics of this casting compound is-suchthata frame structure of great strength and rigidity may be formed. .It is also odorless, substantiallychemically inert in that his .resistant to alkalies, acid, heat, cold, and corrosion. It also adheres or bonds well to metal inserts andq other component parts of the structure. The absence of crevices inthe working face inwhich the-material being treated (material in process) can lodge, provides a permanent magnet structure which in actual practice keeps clean-except for -,the.,tramp iron, and therefore can operate .effectivelyfor longer periods. This pole shoe, a magnetic cement in the gaps forming an adherent mechanical connection between the poles and pole shoes, said cement comprising a mixture of finely divided material having the characteristics of permanent magnets and, a solventless varnish of the unsaturated polyester type set up by addition polymerization without the evolution of Volatile matten'said cement being set up in situ in each gap and a non-magnetic frame for the magnetic assembly comprising a solventless varnish of the unsaturated polyester type set up by addition polymerization without the evolution of volatile matter cast and set up in situ around the poles of the magnet and the adjacent faces of the pole shoes and in the space between the spaced pole shoes.

2. A magnet assembly for magneticseparators comprising a pair of soft iron pole shoes having spaced generally parallel inner edges, each shoe having an exposed Working face, a permanent magnet bridging the space between the inner edges of the pole shoes and having a pole ad- J'acent the face of each shoe opposite its working face, there being a gap between each pole and pole shoe, a magnetic cement in the gaps forming an adherent mechanical connection between the poles and pole shoes, said cement comprising a mixture of finely divided aluminum nickel cobalt type permanent magnet material and a solventless varnish set up in situ without the evolution of volatile matter, and a non-magnetic supporting frame for the magnet assembly comprising solventless varnish cast in situ Without the evolution of volatile matter flush with the exposed working faces of the pole shoes and around the reverse faces of the pole shoes and the adjacent poles of the magnet to provide a rigid structure having a smooth surface even with the exposed working faces of the pole shoes.

NEAL S. MORETON.

References Cited in the file of this patent UNITED STATES PATENTS Number 

